Some time ago a Russian academic visitor told me that there are no "normal" Russian words with the syllable кы. He said that the only words with the syllable кы are proper names given by non-Russian ethnic groups as well as similarly exceptional words such as rarely used borrowed words for some unique non-Russian stuff. He added that although Russians can sometimes say "кыш" when they accidentally encounter a bear in a forest, the word "кыш" is a single three-letter syllable and thus does not count as containing the syllable "кы."
After the conversation, I performed research in Google and got really puzzled: I found neither "normal" Russian words with the syllable "кы" nor explanations for that.
I cannot see any obvious reason for the syllable "кы" being nonexistent. The letters к and ы are not rarely used at all and are the 11th and 17th most freuqently used Russian letters, respectively, with the Russian alphabet containing 33 letters in total. The letter ы is contained even in most basic pronouns - "ты," "мы," and "вы." I can easily find many words with two-letter syllables ending with ы: дыня, пузыри, бычара, лыжи, ныкать, пырять, сычиный, and so on. Although there are apparently no words with жы and шы, the´latter two syllables are simply prohibited by the well-known orthography rule that prescribes writing them as жи and ши, and I am not aware of any similar orthography rule prohibiting кы.
I do not see any phonetics-related reason either, as the syllable кы is pronounced without any difficulties. At least Turkic people have no difficulties pronouncing it, as can be evidenced by their languages. For example, a girl in Turkish is kız (кыз), which is one of the most frequently used Turkish words. The Turkish word for "red" is "kırmızı" (кырмызы). Some Russian geographic names of Turkic origin are written with the syllable кы, e.g., Кызыл, which is a city in Russia.
At some point I thought that the reason for the nonexistence of the syllable кы in Russian might be that this syllable sounds very similar to some frequently used Russian syllable and is replaced by it to avoid phonetic nuances, but later I dismissed this idea. Perhaps the closest syllable is ки, but it sounds differently enough to be easily distinguished from кы. At least the Turks actively use both kı (кы) and ki (ки) in their language. For example, "two" in Turkish is "iki" (ики), and I gave a couple of examples with kı in the paragraph above (kız, kırmızı). After all, if the Russians found it hard to distingsuish between кы and ки, they would probably say and write "киш" instead of "кыш."
My question is this: Are there any "normal" Russian words with the syllable кы, and what is the mysterious reason for their nonexistence or being very few?
I guess that in order to make my question well-defined, I have to define a "normal" word, but it is pretty hard, so I have to appeal to your common sense. A "normal" word is not highly special and, in particular, is not extremely rarely used, is not a proper name of non-Russian origin or its derivative, is not a highly specialized jargon or slang word, is not a rare borrowed word for some unique foreign stuff, etc. A "normal" word is contained in standard dictionaries, is recognized by linguists as a part of the Russian language, is known to almost every Russian, etc. I humbly hope that you get the idea what is a "normal" word. I am especially interested to see Russian words of Slavic origin with the syllable "кы."